The present invention relates to apparatuses and methods for use in manufacturing semiconductor substrates. More specifically, the present invention is directed to unit and method for transferring substrates and apparatus and method for treating substrates with the unit.
In recent years, cluster-type apparatuses are increasingly used to manufacture semiconductor devices. A cluster-type apparatus has a configuration where a loadlock chamber and process chambers are disposed around a transfer chamber. Generally, wafers are placed in a loadlock chamber and vertically spaced to face each other. Two chucks, on which substrates are to be mounted, are provided inside one process chamber and disposed abreast in a side direction.
A transfer unit is provided at a transfer chamber to transfer a wafer between a loadlock chamber and a process chamber and between one process chamber and another process chamber. Since the transfer unit has only one blade on which a wafer is placed, only one wafer can be transferred at one time. In order to mount wafers on their respective chucks, a transfer unit must carry wafers between a loadlock chamber and a process chamber twice. Thus, it takes much time to transfer wafers. In the case where two robots operating independently may be provided at a transfer chamber, an occupied area of the transfer chamber increases due to the two robots. Further, since the two robots cannot enter one loadlock chamber at the same time, one robot must wait until the other robot takes a wafer out of a loadlock chamber.
In addition, a typical transfer unit includes only one holding part where a wafer is placed on a blade. After taking a processed wafer out of a process chamber and putting the wafer into a loadlock chamber, a blade takes another wafer out of the loadlock chamber and carries the wafer to the process chamber. Accordingly, until a process for the next wafer is performed inside a process chamber after a process for a wafer is performed, much time is required for transferring a wafer to significantly decrease a treating amount of the process chamber.